Dynamics of Water Absorbed in Polyamides

Journal article

Publication Details

Author(s): Laurati M, Sotta P, Long DR, Fillot LA, Arbe A, Alegria A, Embs JP, Unruh T, Schneider GJ, Colmenero J
Journal: Macromolecules
Publication year: 2012
Volume: 45
Journal issue: 3
Pages range: 1676-1687
ISSN: 0024-9297


We investigate the dynamics of water absorbed in amorphous and semicrystalline aromatic polyamide copolymers. The combination of dielectric spectroscopy and quasi-elastic neutron scattering experiments allows us to characterize the water dynamics over a wide range of temperatures (dielectric spectroscopy) and at microscopic length scales (neutron scattering). The dielectric investigation evidences two relaxations associated with water motions: a fast process corresponding to motions of loosely bonded water molecules and a slower process corresponding to motions of amide-water complexes. While the slower process presents the characteristic Arrhenius temperature dependence of a secondary local relaxation over the whole temperature range, the fast process shows a crossover from Arrhenius to Vogel-Fulcher-Tamman (VFT) behavior at T approximate to 225 K, characteristic of confined water dynamics. The microscopic investigation by neutron scattering shows than in the VFT regime of the fast process the dynamics present a diffusive nature similar to bulk water. A large distribution of diffusion coefficients indicates possible differences in the connectivity of the hydrogen bond network. Diffusive heterogeneous dynamics can arise from a nonuniform distribution of water. The confinement effect of the polymer matrix is detected as a considerable reduction of the diffusion coefficient of water with respect to bulk. The presence of a crystalline phase results in a slowing down of both the fast and slow processes involving water motions. This could give a hint to the presence of a rigid amorphous phase in the semicrystalline material.

FAU Authors / FAU Editors

Unruh, Tobias Prof. Dr.
Professur für Nanomaterialcharakterisierung (Streumethoden)

External institutions
Forschungszentrum Jülich GmbH (FZJ)
Paul Scherrer Institute (PSI)
Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC)
University of Basque Country / Universidad del Pais Vasco (UPV) / Euskal Herriko Unibersitatea (EHU)

How to cite

Laurati, M., Sotta, P., Long, D.R., Fillot, L.A., Arbe, A., Alegria, A.,... Colmenero, J. (2012). Dynamics of Water Absorbed in Polyamides. Macromolecules, 45(3), 1676-1687. https://dx.doi.org/10.1021/ma202368x

Laurati, M., et al. "Dynamics of Water Absorbed in Polyamides." Macromolecules 45.3 (2012): 1676-1687.


Last updated on 2018-06-08 at 17:23